Mana Leak

Counter target spell unless its controller pays {3}.

Island

Thought Scour

Target player mills two cards.
Draw a card.

Echoing Truth

Return target nonland permanent and all other permanents with the same name as that permanent to their owners' hands.

Counterspell

Fallaji Archaeologist

When Fallaji Archaeologist enters, mill three cards. You may put a noncreature, nonland card from among the cards milled this way into your hand. If you don't, put a +1/+1 counter on Fallaji Archaeologist. (To mill a card, put the top card of your library into your graveyard.)

Spire Golem

Affinity for Islands (This spell costs {1} less to cast for each Island you control.)
Flying

Rush of Knowledge

Draw cards equal to the highest mana value among permanents you control.

Frantic Inventory

Draw a card, then draw cards equal to the number of cards named Frantic Inventory in your graveyard.

Mental Note

Tolarian Terror

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)

Insectile Aberration

Delver of Secrets

At the beginning of your upkeep, look at the top card of your library. You may reveal that card. If an instant or sorcery card is revealed this way, transform Delver of Secrets.

Delver of Secrets // Insectile Aberration

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.